The present invention is an observer's tool that is manually set to visually identify the phase of the Moon in the sky. When set, the chart simultaneously correlates the Moon's orbital position, the day of the lunar month, the time period the phase is visible, and various other aspects of the Moon/Earth/Sun relationship.
For centuries, moveable wheel charts have been used as field guides to locate and learn about stars and constellations in the night sky.
A moon phase wheel chart and moon phase device are known, as in U.S. Pat. Nos. 5,974,001 and 7,251,198B2, both to Barton, however both inventions are devices designed to determine the moon phase of a particular date. These do not explain or show why the Moon displays phases, nor do these references inform the user how to relate what they see in the sky to the Moon's orbit around Earth.
Therefore, there is a need for a device that can simply illustrate and explain how and when moon phases happen, the device being inexpensive, small and lightweight for easy use in the field. Such a device should be understandable to the layperson, and be able to impart a fundamental understanding about the relationship of the Moon, Earth and Sun.